The present invention relates to encapsulation systems and methods for toxic substances.
There are three major toxic substances addressed in the EPA's Toxic Substance Control Act (TSCA): molds, lead and asbestos. Other toxic substances worth noting include biohazard and chemical toxins such as blood-borne pathogens and chemical residues at crime scenes. Toxic substances are typically introduced into the body through inhalation, ingestion or absorption.
While TSCA bans the manufacture, processing, use and distribution of certain toxins, the fact remains that many older structures were constructed using materials manufactured with toxins. Other toxins may also be present due to naturally occurring phenomenon or due to human activities. When present, each toxic substance presents the occupants of the structure with the challenge of mitigating potential health effects.
Current methodologies for management, cleanup and disposal of environmental toxic substances fall under the guidance of the EPA, OSHA and state agencies. Two generally utilized strategies for mitigation are removal or encapsulation. Either strategy depends on development of containment areas that isolate toxic substances from adjacent settings to minimize the areas of contamination.
To be effective, containment requires sealing off the affected area using plastic or polyethylene sheeting. The sheeting is stapled, taped or otherwise secured to the walls, ceilings and flooring to create an isolated environment in which to begin remediation. Generally, the workers are clothed in protective suits and use respiration equipment that filters airflow, preventing toxins from being inhaled.
In the containment chamber, a number of activities might take place. Where moisture is present, one or more dehumidifiers are put to work. One or more air scrubbers might be used to draw air through a series of filters designed to extract toxic particles from the air. Many times, the official recommendation is to apply a mist of water to the environment in hopes of weighting down small particles rather than having them airborne. The heavier particles are then removed using standard cleaning techniques.
In every instance the purpose of containment, removal and remediation is to prevent the toxic substances from contact with humans through inhalation, ingestion or absorption. Generally, toxic substances are most likely to be inhaled. The greater the concentration of airborne toxins, the longer the exposure to the airborne toxins, the greater there will be a likelihood of toxicity in humans and other animals.
Molds and other fungi grow where there is moisture and a food source. Moisture may be introduced by naturally occurring environmental conditions such as high humidity, normal precipitation, flooding, or ground water issues. Mechanical failures such as leaking pipes, water heater failures or damp basements may also be a source of moisture. The food source can be something as simple as sheetrock or wood. Mold spores may enter the structure through normal airflow and lie dormant for extended periods until moisture is introduced. Then, molds propagate quickly creating a potential for human interaction. Because mold spores range from 3-100 microns in size (some as small as 1 micron), they easily become airborne with the normal airflows created by the typical air conditioner or heater. Once airborne, these tiny particles can infiltrate furnishing, clothing, food and equipment, such as air conditioners that can spread them throughout the building. Most importantly, these tiny mold spores can be inhaled, potentially with toxic effect.
While not all people are equally sensitive to the effects of all types of mold, some are more adversely affected than others. Those more likely to be affected include infants, children, elderly people, pregnant women and individuals with weakened immune systems, allergies, and asthma. Studies have shown causal relationships between these fungi and respiratory disease, toxic dust syndrome, hypersensitivity pneumonitis, allergic lung disease, infant idiopathic pulmonary hemorrhage, Stachybotrys-induced lung injury, neurotoxicity, carcinogenicity, acute liver injury, endocrine toxicity, renal and urological toxicities and complications of pregnancy.
Mold is often found growing under the structure on floor joists. It is also found in bath and shower areas, laundry rooms, under cabinets and on walls. Many times, it is found inside walls and under flooring.
Once mold is revealed, the likelihood of spores becoming airborne increases greatly. Based on the intensity of the mold and the sensitivity of the occupants, a decision has to be made whether to stay and endure or evacuate the premises until the remediation process has been completed. Waiting for the containment, drying, removal, repair and cleanup can be frustrating, costly and time consuming. The remediation process may include sanding the mold off fixed surfaces like floor joists, then painting the sanded surfaces with an antifungal paint.
What is needed in the art is something that quickly and effectively prevents mold spores from becoming airborne.
Lead contamination is equally toxic. According to the EPA, the most common way to get lead in the body is from dust. Lead dust from decaying lead-based paints, used in older structures, can be found on surfaces like air conditioners and flooring. Dust may accumulate to unsafe levels. Then, normal hand-to-mouth activities, like playing and eating (especially in young children), move that dust from surfaces like floors and windowsills into the body. The health effects include damage to the central nervous system, circulatory and blood-forming systems, reproduction system, kidneys and gastro-intestinal tract. Especially sensitive people include children six years and younger, as well as, prenatal children.
The EPA; OSHA; HUD and state regulatory authorities recommend encapsulation when possible and removal where absolutely necessary. As with remediation of mold, keeping particulate from becoming airborne is key to minimizing the damaging health effects. This may mean removing occupants from the structure during restoration or removal. It includes containment and wetting the area. Special hazardous material disposal methods are mandated. Expect this process to be equally time consuming, more cumbersome, and even more costly than mold remediation.
Lead may also be introduced into the environment through lead pipes and lead solders. Here, lead contaminates may be introduced through ingestion or absorption from drinking, bath and laundry waters. If used as a source for watering gardens, absorption may be through ingestion of produce. Replacement is the preferred solution for this contaminant, however, encapsulating the pipe and using an alternate piping source would be possible.
What is needed in the art is something that quickly and effectively prevents lead dust from becoming airborne.
Asbestos is a mineral fiber that has been used commonly in a variety of building construction materials for insulation and as a fire retardant. The term “asbestos” generally refers to six fibrous minerals: tremolite asbestos, actinolite asbestos, anthophyllite asbestos, chrysotile asbestos, amosite asbestos, and crocidolite asbestos. When asbestos-containing materials are damaged or disturbed by repair, remodeling or demolition activities, microscopic fibers become airborne and can be inhaled into the lungs where they can cause significant health problems including asbestosis, lung cancer and mesothelioma.
This high profile toxin is prevalent in structures built prior to 1978. Beginning in 1979, federal regulations prohibited manufacturers from using asbestos in building materials. While removal was once considered the preferred method of addressing asbestos, current guidelines recommend the asbestos be left undisturbed and encapsulated.
Specifically, NESHAP regulations address both friable asbestos and non-friable asbestos that have become friable. Friable asbestos is defined as easy to break or crumble by hand. It has a high probability of releasing asbestos fibers into the air. Normally, these substances have become friable due to weathering, normal deterioration over time, excessive use or exposure to chemicals or high heat. Examples include: acoustical plaster, spray-applied insulation, duct connectors, insulation and pipe coverings. Non-Friable asbestos is defined as difficult to break by hand and has a low probability of releasing fibers into the air. However, Category I Non-Friable materials, which are unlikely to be made friable, are recommended for removal only if they are in very poor condition. Otherwise, they should be encapsulated. This category includes vinyl floor coverings and vinyl asbestos tile. Category II Non-Friable materials include all not Category I, materials more likely to be made friable, as they are not resistant to weathering or crushing forces and may be subjected to extreme conditions or excessive use.
Common asbestos products may be found in basements, roofs, outdoor siding, ceilings (especially acoustic ceilings or “popcorn” ceilings), flooring, attics and plumbing. It was often used in insulation, patching compound, joint compound, cement sheets, millboard, paper insulation, heating insulation, and fireproofing. Materials applied to walls and flooring that may contain asbestos include soundproofing material, decorative or textured paints, vinyl floor tiles, asphalt tiles, rubber tiles, insulation board on walls, acoustical plasters or paints, spackle, ceiling tiles, caulking or putty, adhesives and cement pipes. Asbestos may be present in basements, the exterior of homes and household appliances such as: roofing shingles, exterior siding, steam pipes, boilers, furnace ducts, and gaskets, wood or coal stoves.
Asbestos in a home or building can be dealt with in four main ways: enclosure, encapsulation, repair or removal. Complete removal of asbestos-containing materials is known as asbestos abatement, the most dangerous option, as there is a high risk for airborne asbestos particles during removal of ACMs. Removal of asbestos must be done in compliance with NESHAP asbestos regulations and disposed of in a specially designated hazardous waste facility.
As with other toxic substance remediation, asbestos removal requires significant resources. These include creating a sealed containment area, using plastic sheeting and duct tape; ventilation to the outside; and protective clothing. Creating a wet room to minimize airborne particulate is highly recommended. Because of the high standards necessary to safely remove asbestos, other factors will influence the decision. These are the size of the job (square foot area); type of material or surface; the type of asbestos fibers present; condition of the asbestos (painted over, water-damaged, flaking, etc); accessibility of the material; ability of the work area to be sealed off and made air-tight; and airflow through the work area.
What is needed in the art is something that quickly and effectively prevents asbestos fibers from becoming airborne.
Bio-hazardous and chemical contaminants can pose serious health risks. Blood-borne pathogenic substances resulting from accident, trauma, crime or death; crime scene residues such as tear gas or pepper spray; and toxic chemical residues such as those left in the wake of a methamphetamine lab fire are toxic substances that can pose serious health consequences for occupants of affected buildings, law enforcement professionals, and cleanup personnel.
Blood can contain such toxins as HIV; Hepatitis B; and Hepatitis C. Professional cleanup organizations follow blood-borne pathogen universal precautions by sterilizing broken glass, removing furniture, mattresses and other transportable items that have been contaminated, and removing visible bio-hazardous materials in properly labeled waste containers. This step is followed by assessing the extent of damage underneath carpeting, in flooring or on walls. Wooden flooring, linoleum and drywall may require removing to prevent continued odors and prevent attracting bugs and animals (from odors than might emanate).
Tear gas and pepper spray residues at crime scene can prove equally toxic to personnel examining the scene. Deployed tear gas penetrates windows and walls leaving pockets of heat and moisture activated carcinogen. Unmitigated residues expose occupants to skin, eye and lung irritation.
Toxic chemical residues, such as those found in methamphetamine lab crime sites, pose serious risk to inhabitants, personnel on the scene and cleanup crews. The volatility of the residues requires special HAZMAT teams to effectively remove all toxins. While requirements for cleaning do vary from state to state, ventilation along with protective clothing is always required.
What is needed in the art is something that quickly and effectively prevents pathogens and toxic residues from becoming airborne.
Many toxic substances, found in structures such as homes and businesses, consist of small particulate.
Should these inert toxic particulate be subjected to even the slightest of forces; such as caused by heating and air conditioning systems; airflow from open doors or windows; changes in barometric pressure; or physical disturbance, they are lifted off their resting places and float upon whatever air currents that are present.
Because humans and other living creatures may be present in an environment where air currents are supporting toxic particulate, the floating toxic substances are likely to be affected by secondary airflows; such as those created by the process of inhalation. Therefore, during the process of inhalation, airborne toxic substances are inhaled into the bodies of humans and other living creatures.
Once inside a body, toxic substances are deposited on various organ linings, such as lung tissues, and subsequently processed through various organs. As toxic substances are generally incompatible with normal bodily functions, it is likely that various adverse health effects are created. Examples of such are bronchial distress, lead poisoning, or lung cancer.
In that introduction of toxic substances into a body is generally considered undesirable and that toxin-free air is the safest way to avoid these health hazards, it is desirable that a potentially toxic environment be remediated of toxins as quickly and thoroughly as possible. Currently, there are several variations of toxic substance remediation and abatement methods utilized by remediation specialists; recommended by governmental health organizations such as the EPA; OSHA and state entities; and individuals. Each method begins with containment and is followed by either encapsulation or abatement.
Under current methodology, once the site is deemed to need containment, the remediator, clothed in safety apparel and possibly with air being filtered by use of a respirator, will seal off the affected area by creating walls of plastic sheeting attached securely with staples, tape or other means so that the only means of airflow is through windows, doors or other ports to the exterior of the building. Once containment is effected, if abatement follows, current methodology would dictate materials being removed be secured through cleaning, encapsulation or a combination of both.
Cleaning methods differ from one toxic substance to another; however, the most prevalent methods require a wetting process whereby the areas, affected by toxic substances, are saturated with moisture. The desired intent is to have the moisture fall upon the toxic substance particulate, thereby rendering it too heavy to be supported by air currents and be subjected to inhalation by humans and other animals.
Because wetting the containment area during the cleaning process introduces moisture, a subsequent drying process must be employed. The subsequent drying process typically takes place in the containment area using a combination of both air dryers to draw moisture from floors, walls and cabinets along with air scrubbers to filter and remove whatever disturbed airborne particulate was not removed during the cleaning process.
Cleaning methods using containment areas, wetting processes, drying efforts and air scrubbing require many hours of skilled labor, many raw materials and may take days to complete. Some toxic substances like mold are regenerative and when left unattended for as little as 48 hours can grow. Since some jobs take days or weeks to complete, the likelihood of accelerated airborne toxins increases.
While the containment method that uses wetting, cleaning, drying, air scrubbing and safe disposal may be used for some sites where the toxic substances are abated or removed, for other sites encapsulation is the preferred method. This widely used remediation method, encapsulation, similarly uses steps of containment, wetting, cleaning by scraping or sanding surfaces, drying, air scrubbing and safe disposal of toxic substances. Examples of remediation by encapsulation include are mold, lead and asbestos, to name a few.
After the affected areas are rid of the toxic substances, the remediator proceeds to apply by brushing, rolling or spraying “liquid paints” such as chemical biocides for molds or others that might be suitable for lead or asbestos. For some toxic substances, removal or cleaning is adequate; nonetheless, there are recommendations from the EPA, OSHA and state agencies that call for not disturbing the area except to fully encapsulate. One such example is asbestos because in its inert unchanged state, fewer carcinogenic fibers will be released into the air. For brittle or friable toxic substances, such as lead paint or asbestos, the common method of encapsulation is to apply, by brushing, rolling or spraying, one or more layers of selected liquid coats that are similar to paint in consistency. For multiple coats, the curing times may take as long as two weeks.
For some toxic substances that need to be remediated, another method is to encapsulate or encase the affected areas using common building materials such as gypsum wallboard. With this method of encapsulation or encasement the materials laminated to the affected surfaces are sealed with liquid bonding adhesives. This method is costly in labor, raw materials, as well as, installation time.